java.lang.RuntimeException: Unable to start service com.dexterous.flutterlocalnotifications.ForegroundService@1985771 with Intent { cmp=com.xxx.xxx/com.dexterous.flutterlocalnotifications.ForegroundService (has extras) }: java.lang.NullPointerException: Attempt to invoke virtual method 'int java.lang.Integer.intValue()' on a null object reference

E/AndroidRuntime(11842): java.lang.RuntimeException: Unable to start service com.dexterous.flutterlocalnotifications.ForegroundService@1985771 with Intent { cmp=com.zhanghongyang.todo/com.dexterous.flutterlocalnotifications.ForegroundService (has extras) }: java.lang.NullPointerException: Attempt to invoke virtual method 'int java.lang.Integer.intValue()' on a null object reference
E/AndroidRuntime(11842): at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:5408)
E/AndroidRuntime(11842): at android.app.ActivityThread.access$3200(ActivityThread.java:283)
E/AndroidRuntime(11842): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2584)
E/AndroidRuntime(11842): at android.os.Handler.dispatchMessage(Handler.java:109)
E/AndroidRuntime(11842): at android.os.Looper.loopOnce(Looper.java:206)
E/AndroidRuntime(11842): at android.os.Looper.loop(Looper.java:296)
E/AndroidRuntime(11842): at android.app.ActivityThread.main(ActivityThread.java:9047)
E/AndroidRuntime(11842): at java.lang.reflect.Method.invoke(Native Method)
E/AndroidRuntime(11842): at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:582)
E/AndroidRuntime(11842): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:968)
E/AndroidRuntime(11842): Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'int java.lang.Integer.intValue()' on a null object reference
E/AndroidRuntime(11842): at com.dexterous.flutterlocalnotifications.FlutterLocalNotificationsPlugin.setSmallIcon(FlutterLocalNotificationsPlugin.java:463)
E/AndroidRuntime(11842): at com.dexterous.flutterlocalnotifications.FlutterLocalNotificationsPlugin.createNotification(FlutterLocalNotificationsPlugin.java:364)
E/AndroidRuntime(11842): at com.dexterous.flutterlocalnotifications.ForegroundService.onStartCommand(ForegroundService.java:29)
E/AndroidRuntime(11842): at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:5388)
E/AndroidRuntime(11842): ... 9 more
I/ClientTransactionHandler(11842): send EXECUTE_TRANSACTION
I/ClientTransactionHandler(11842): send EXECUTE_TRANSACTION
I/Process (11842): Sending signal. PID: 11842 SIG: 9

Start with the stack trace in FlutterLocalNotificationsPlugin.java at setSmallIcon (line 463), then inspect createNotification (line 364) and ForegroundService.java (line 29). Reproduce the foreground-service startup failure and determine why a null Integer reaches setSmallIcon; done means the service starts without this NullPointerException and creates its notification.